CDC Definition of Terms
As of"Immunity", "Vaccine", "Vaccination" & "Immunization":
IMMUNITY: Protection from an infectious disease. If you are immune to a disease, you can be exposed to it without becoming infected.
VACCINE: A product that stimulates a person’s immune system to produce immunity to a specific disease, protecting the person from that disease. Vaccines are usually administered through needle injections, but can also be administered by mouth or sprayed into the nose.
VACCINATION: The act of introducing a vaccine into the body to produce immunity to a specific disease.
IMMUNIZATION: A process by which a person becomes protected against a disease through vaccination. This term is often used interchangeably with vaccination or inoculation.